I get some ribbing from some fishermen/guides about wearing camo. (Some about carrying a big net too). The two may be related.
The fish here don't like getting caught, and so, have raised the bar.
The best chance to catch Walter in smallish clear water, is to not let him know you are there. I say give them everything they want, and none of the things they don't want.
Mostly I think they pick up movement, but sound and color play a part too.
Many years ago, I was getting blanked. I couldn't figure it out. I was sneaking up a steep granite slide below a plunge pool. Noone fished this creek, and I knew my shut out was going to change on this pool. My new fishing hat (light colored straw) got there first. A huge V went away from me, and the light bulb lit above my head.
Natural Gear is a great company for camo clothing.
Long sleeves in nylon (quick drying), and a very good all around pattern. ( I don't fish in cattails, or heavy woods.) Tell'em I sent you.
Difficult to say how much it improves your chances at a fish, but I can't spook them, and then hope to get a client into them.
To me, all the little things add up.
This winter I went white.

Yeah, I got a bunch of snickers and chuckles up on the Madison River, down in the Channels section near Ennis...until some of the Yups saw my rod bend repeatedly...use of shadow and uptight along brush and trees on the islands...after I had first fished through it- flat finished rod and no mirrored sunglasses.

Up where you are, the Trout take a pounding...I fish as far up as the EFCR below Markleeville. Any point from Olancha up, I can generally be found in camo...

Natural Gear is a good neutral pattern. I wish it had been around when I hunted the Yip Dogs...

I grew up a turkey hunter and a bow hunter. I have always worn either woodland print or olive drab when fishing in conditions where it would be likely the fish may see me. It has always been common place for me to think this way.

Had a guy get out of his car 300+ yards away, saw a flash, figured it was a warden. Turned out it was a fisherman, his retractor for his hemostats was chrome.
Everytyhing counts.
I like PTrout's comment on flashy finished rods, should be standard issue flat.
The mirrored glasses thing cracked me up!

I used to fish a small lake in te middle of a town I used to live in for Largemouth. They were very wary of people walking the shoreline. For this reason I sewed a camo fly vest, pants and bought a matching shirt and hat. I walked slow and caught way more fish. If you put on just an orange or white hat you could walk the same shore and watch Bass head deep as you approached. Some places I'm sure it does not matter, but places like there camo was really a help. And don't bust my chops for sewing

I think there are two things that might effect game. Movement and something that doesn't blend with the background. With fish I think it is all movement. I don't think bright contrasting colors bother a fish. But, bright and contrasting colors may make it easier for the fish to see movement. Who knows??

I'm with you Frank. Who knows? It is a subjective thing. No way to test this scientifically.
I have had some clients who have dressed loudly in summer (white dress shirt), and couldn't buy a fish. You may be correct that light colors just betray our movement.
This winter I tested white camo, I'd say it definitely helped me get the sneak on.
Dark colors stand out like a sore thumb on a snowy background.
If you have game and aren't getting into fish, it's worth a try.
Dan, wish I had a sewing machine!